U. S. Pat. No. 4,719,880, issued Jan. 19, 1988, discloses a two stroke cycle engine having a cylinder with intake and exhaust ports controlled by reciprocation of a shallow domed piston. A cylinder head closing the cylinder has a concave face opposing the piston dome and a combustion chamber cavity of specific shape, offset toward the inlet port side of the cylinder.
U. S. Pat. No. 4,969,329, issued Nov. 13, 1990 to the assignee of the present invention, discloses a somewhat similar engine cylinder arrangement with an offset combustion chamber cavity. However, the head or top wall of the piston and the opposing end of the cylinder (except for the cavity) are flat.